A general gas turbine includes a compressor, a combustor, and a turbine. Air introduced from an air inlet is compressed by the compressor into compressed air at a high temperature and high pressure. In the combustor, fuel is supplied to the compressed air to cause combustion, thereby obtaining a combustion gas (working fluid) at a high temperature and high pressure. The turbine is driven by the combustion gas, thereby driving a generator coupled to the turbine.
Fuel is supplied to a combustor through a plurality of routes. For example, in Patent Literature 1, a gas turbine plant is described in which a plurality of main combustion burners is disposed so as to surround a pilot combustion burner, and supply is made through each of a fuel supply system for supplying fuel to the pilot combustion burner and a fuel supply systems for supplying fuel to the plurality of main combustion burners. In addition, a plurality of fuel supply systems for supplying fuel to the plurality of main combustion burners is provided in Patent Literature 1. Furthermore, in some gas turbines, fuel is supplied from a top hat nozzle besides a main nozzle and a pilot nozzle. Such a gas turbine including a top hat nozzle is provided with a fuel system for supplying fuel to the top hat nozzle.